Wireless communication systems are widely deployed to provide various types of communication such as voice and data for a number of associated users. These systems may be implemented based on various access techniques such as, for example, code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), or some other multiple access techniques.
A multiple-input multiple-output (MIMO) communication system employs multiple transmit (NT) antennas and multiple receive (NR) antennas for communicating multiple spatially independent data streams. In an exemplary MIMO downlink communication system, the transmitter (e.g., a base station) is provided with multiple antennas capable of transmitting multiple spatially independent data streams, while the receiver (e.g., a mobile device) is equipped with multiple receive antennas to receive one or more of the multiple spatially independent data streams transmitted by the base station. The connection between the multiple-antenna base station and a single multiple-antenna mobile device is called a MIMO channel, which is formed by multiple (NT) transmit antennas and multiple (NR) receive antennas. A MIMO channel may be decomposed into NC independent channels, with NC≦min {NT, NR}. Each of the NC independent channels is referred to as a spatial subchannel of the single user downlink MIMO channel. Different MIMO channels experience different link characteristics and are associated with different transmission capability.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.